Need tube 101 info

Last_lemming...with regards to your last question, I would recommend calling BAT's customer service/technical support folks to walk you through what the difeerent tubes do and if they have recommendations on which sets impact the sound more than others. Also ask them if they have recommendations for certain NOS tubes in each of the slots. You will likely get an explanation of the first question for sure (what the tubes in different slots do and which to tube roll first for bigger impact on sound) and less likely to get specific recommendations on what NOS tubes to try out (although you never know).

The other respected source you will find often talked about on Agon when it comes to tube rolling (although somewhat controversial) is Upscale Audio. They carry BAT and the owner will have strong opinions about what tubes to roll. He sells NOS and current production tubes and he may be another good source to talk to. Good luck.

I have been following your story about this new BAT preamp in your other threads, as well, with interest. Here's what I know for sure. BAT preamps, tube or solid state, don't make noise. I have nothing to do with the company and don't currently own any BAT equipment but I know your problem is not normal. I know people that have used BAT amps and preamps with ultra efficient speakers, like horn designs, and they are dead quiet even under the most demanding applications.

In my opinion, this is the safest and easiest way to get to the bottom of what your problem is. 1. Call BAT. I'm pretty sure that you have some tube issues. Given your explanations in the other threads, I'm not 100% convinced, though. I would explain the problem to BAT and see what they say. You have nothing to lose and BAT is very concerned about quality issues. 2. If you do need tubes, try to go about it with 0 risk. I recommend The Cable Company. Yes, they are known for cables, but they sell a huge amount of tubes, as well. They are also known for their lending program. They lend me all kinds of stuff other than cables to try before I make a purchase. I am fairly certain that they will lend tubes as well, but you will need to ask them. 3. I know in the other thread, I said you made a good purchase. I stand by it. You probably just need a new set of tubes. Don't make a nightmare out of this for yourself. Get the preamp working, listen to some music and don't 2nd guess every little thing. You'll see what I mean once you get the preamp working.

Get a hold of Jim Mcshane and ask about the current New Sensor Gold Lion series of 6922, and 6V6 tubes, which I believe your preamp uses.

Thanks for everybody's help. I will call BAT tomorrow. The preamp looks well looked after. No scratches and no dust on the inside. I know that doesn't tell the whole story, but it's a nice thing to know. The crackling sound is faint and did switch sides when I switched tubes, so I'm fairly confident it's tubes, but when I talk to BAT I'll see what they say. As for sound quality it is quite a nice match and sounds great on the Thiels. There is something palatable about the music now, and I think I made a good choice. If it should be a bad cap or not tube related, well off to BAT it will go, and my really good deal just becomes fair deal.

Last, try this site for basic tube info: http://www.vacuumtubes.net/How_Vacuum_Tubes_Work.htm. I know I've seen another site that had good audio-related tube info but I can't seem to find it right now. Maybe others will recommend a site. I'm not sure a conversation with BAT will be helpful re: NOS tubes. My understanding is that they don't recommend using NOS tubes. However, I had an email conversation with Viktor when I first bought my VK-3i and he was very gracious. - Dick